COMPUTER MOTIVATIONS AND ONLINE NOTES

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Those parts of the computer which we can touch are all called hardware parts. The hardware part of the computer is divided into four parts. Take what is mentioned in the chart of IPOS below.

Input Device :-

Any instruction and data can be entered into the computer only through Input Device, then the computer processes it, and gives us the output.

Key board :-

It is one of the most used input devices. It works on the principle of typewriter. With this, text, number, symbol etc. are inputted inside the computer. A standard keyboard has 101-105 keys. Multimedia keyboards have more keys than this.

There are many types of keyboards depending on the technology.

Wired (PS2, USB)

Wireless

Bee Raider

Hologram

Key mouse Keyboard

Mouse :-

It is the most commonly used pointer input device in the GUI interface. It has a total of three buttons. There is a left and right button and a scroll button in the middle.

Depending on the technology, there are many types of mouse.

Optical, Wired (PS2, USB)

Wireless

Touchpad

Mechanical

Scanner:-

With this we can directly input information and data inside the computer. With this, after reading any book photo and other data, it saves it as a photo in the computer. With this we convert hardcopy into soft copy. The biggest advantage of using a scanner is that it does not require the user to type the information. You can edit the scanned data with the help of software.

OMR :-

Its full name is Optical Mark Reader. It is a device that checks the presence and absence of a pencil or pen mark on the OMR sheet. This machine only checks the OMR sheet. Nowadays it is used to check the answer book of competitive examination. Its use gives correct results in less time.

OCR :-

Its full name is Optical Character Recognition. With its help, OCR standard characters are identified by looking at the differences between the characters already printed. Through this, the typewriter can read old handwritten articles and credit card characters.

MICR:-

The full name of MICR is Magnetic Ink Character Recognition. It is used more in banking. They are used to check a large number of checks in the bank. In MICR technology, characters are printed on the check by special magnetic ink. MICR reader reads the character printed on the check by sensing the magnetic coil. And it checks. Whether the check is correct or not, the letters which are printed on the check. He writes with magnetic ink.

Light Pen:-

Light pen is used to create a picture or a shape on the computer screen. This is also a pointer device. Light pen has a photo cell. When we make a picture on the computer screen with the light pen. So its pulse is transmitted from the screen and saved in the computer. Lightpen can also be used to select menu option. Nowadays it is being used more in CAD works.

Joystick:-

It is used to play games on the computer. The shape present on the screen can be easily moved through the joystick. This is an easy way to teach computer to kids. This makes it convenient to play games. It is used to control the robot.

Trackball :-

It is a pointer device. It works like a mouse. It consists of a raised ball. And there are two or three buttons, its ball is rotated with the fingers. It works like mouse in laptop. Games are also played with its help. It occupies less space. In this only the ball has to be rotated, not the whole trackball device.

Touch Screen:-

Touch Screen is being used nowadays in banking, railway, airport and library to find the catalog file. The entire touch screen monitor has a sensitive screen. Which is made up of many points. Which we call touch points. It also has a keyboard. By which data can be input into the computer. This technology is user friendly. It is easy to operate it. In this, the work of the mouse is done by the fingers. The option that has to be selected. Touches it with fingers.

Digitizing tablet or Graphic table:-

Digitizing tablet is a drawing surface. It is accompanied by a pen or mouse. There is a thin wire mesh on this table. On which the signal goes to the computer as soon as the pen is operated. A scanning head is placed on top of it. Which is called Puck. It is used to get the letter in the desired graphical position. With the help of this graph can also be constructed. That's why it is also called graph table.

Bar Code Reader (BCR):-

BCR is used in the commercial field. This is done to read the bar code printed on the top of the product packet. Due to which complete information about the product is input into the computer in one go. And then processing is done on it. In this, optical method is used to read the barcode. There are two types of BCR.

1. Flatbed:-

It is set on the table. And the bar code of the product is read by placing it on it.

2. Handheld:-

They are used by taking them in hand. It is used in small markets, couriers and post offices.

Processing Unit:-

Processing unit works to process the input data, we can get the processed data through the output device. Processing consists of the following units. Processor (CPU), Motherboard.

Processor :-

The combination of ALU and CU is called processor. Usually the processor itself is called CPU. Processor speed is measured in MIPS (Million Instructions Per Second).

CPU :-

The full name of CPU is Central Processing Unit. This is the brain of the computer. The job of the CPU is to execute instructions or programs. CPU is made up of the following units.

CU

ALU

General Purpose Registers (MU)

1. CU:-

Its full name is Control Unit. The CU works to control all the functions of the entire computer system. This unit is an important unit of CPU.

2. ALU:-

Its full name is Arithmetic Logical Unit. It is the main unit of computer. Through this all the arithmetic and logical work is done in the computer. It happens inside the processor.

3. General Purpose Registers (MU):-

It is a part of the CPU itself, which works to store data at the time of processing. This is the fastest memory of the computer, because it is closest to the CPU.

Motherboard:-

All the electronic components in a system are mounted on a piece of fiberglass called the mother board. Motherboard works to connect all the parts of the computer.

Output devices:-

Monitor is an output device. It is also called visual display unit. It looks like a TV. Monitor is one of the most important output device. Without it the computer is incomplete. It displays the output as a soft copy on its screen.

CRT (Cathode Ray Tube) Monitor:-

This technology is capable of giving cheap and colorful output. It has a picture tube element. Which is like the old TB set. This technology has stopped.

Flat Panel Monitor:-

These thin display devices are called Flat Panel Display. It is being used in laptops, it reduces the consumption of electricity. and are light in weight. It has LCD (Liquid Crystal Display)

Technology is used. The names of two other flat panel technology are GPD (Gas Plasma Display), Electroluminescent Display (EL). Their display quality is better than LCD. Today's new technology is LED. Whose full name is Light Emitting Diode.

Characteristics of a Monitor

1. Resolution:-

The important quality of a display device is the resolution or the clarity of the picture of the screen. The formation of the picture in the monitor is made up of small dots. Which is called a pixel when this point shines. So the picture is formed. The number of points present in the unit area represents the resolution. The resolution capacity of the monitor should be high. The higher the resolution, the greater the clarity of the picture.

2. Dot Pitch:-

Dot pitch is a type of measurement technique. which it displays. What is the horizontal difference or distance between two pixels. It is measured in millimeters. It displays the quality of the monitor. The dotpitch in the monitor should be low. It is also called phosphor pitch. The dot pitch of a color monitor ranges from 0.15 MM to .30 MM.

Printing Technology:-

Printer:-

Printer is an output device. From this the output is printed on paper and presented. The output taken on paper is called hard copy.

Impact Printer:-

These are the printers. Who makes sound while printing. That's why they are called impact printers. There are two types of impact printers.

1. Dot Matrix printer

2. Solid printer

Dot Matrix printer:-

It is an impact printer. There is a matrix of pins in their print head. By colliding these pins with the ribbon, printing is done on the paper. In this, letters are formed by joining small dots. Their printing head has a horizontal group of 9, 14, 18 or 24 pins. One column at a time takes out the pin head and prints the dots. By which a letter is formed in several steps. Thus the pinting head is pulled forward in the direction of the line. In this the printing head is controlled by computer. Their printing speed is 30 to 600 characters per second. These printers are of two types on the basis of printing quality.

1. Draft Quality Printing:-

It has normal printing.

2. Near Letter Quality Printing:-

In this printing one letter is printed twice. Its printing speed is slow.

Solid Printer:-

Daisy Wheel printer:-

It is a solid font printer impact printer. Daisy wheel is so named because its printing head shape is similar to that of a daisy. Daisy wheel printer is a slow printer but has good printing quality and clarity. That's why it is used for printing letters, so it is also called letter quality printer. Its printing head has a wheel. In which a letter is embossed on each warp, it has a small hammer which strikes the warp and behind the ribbon with the warp is the paper on which the letter is printed. Printing is done by wheel fumigation. And the wheel keeps on moving in its horizontal motion while printing.

Non-Impect Printer:-

They are non-impact printers. Which does not make sound while printing. It is called non impact printer. Their printing speed and clarity are higher than impact printers. There are two types of Non Impact Printers.

1. Ink Jet Printer

2. Lesser Printer

Ink Jet Printer:-

Ink jet printer is a non impact printer. In which characters and pictures are printed by spraying drops of ink on the paper with a nozzle. The ink droplets are charged into the nozzle of the printing head and released in the appropriate direction on the paper. The printout of this printer is more clear. Because in this the formation of the letter is made up of many dots. Color inkjet printers have four nozzles of ink. Blue, Red, Yellow, Black That's why it is also called CYMK Printer. One of the main problems with this printer is that ink clogging occurs in its print head if it is not printed for some time. Ink settles at the mouth of its nozzle. Due to which its pores are closed. This problem is called ink clogging. Nowadays this problem has been solved. Apart from this, if moisture comes on the printing of this printer, then the ink spreads. Its printing quality is usually 300 DPI (Dot Per Inch).

Lesser Printer:-

It is a non impact page printer. It is being used in computers since the 1970s. Earlier these were used in mainframe computers. In the 1980s their cost was $3000. And at the same time they started being used in microcomputers. It is the most popular printer nowadays. Because their printing speed and quality are very good. Laser printer works on the basis of xerography technology. Xerography technology was developed for the Xerox machine. Xerography is a photography technique. In which film, a coating of a charged material, is a dum. This is dum photo sensitive. By this the output is printed on the paper.

Procedure :-

Printing in a laser printer is done using a laser beam, in which the laser beam is focused by lenses on a sputtering polygonal mirror. From where this laser beam of the output is reflected and focused again by the lenses on another mirror. From where this ray gets reflected and falls on the drum. This beam is cast in the form of lines printed on the drum. When this drum beats. So the toner sticks to the charged places. The toner is then transferred onto the paper. Due to which the output is printed on the paper. This output is temporary, to make it permanent, it is passed through a hot roller. Due to which this printing becomes permanent. Most laser printers have microprocessor, RAM and ROM. ROM contains programs to organize fonts and pages. Their printing quality ranges from 300 to 600 Dpi (Dots per inch) which is the best. Colors can also be taken by this. Its printing speed is high. Its speed is measured in PPM (Pages per minute). Nowadays their price has come down. It is an output device that prints pictures and graphs. It prints banners, posters etc. It is of two types.

1. Drum pen plotter

2. Flat bed plotter

Drum pen plotter:-

This is a plotter in which pens are used. Which by moving creates a picture or figure on the paper. In this, the paper is mounted on the drum which gradually slips and the pen printing goes on. It acts like a mechanical artist. Technical Drafting Pen is used in these. The speed of the pen is equal to one thousandth of an inch at a time. Many platters have four or more pens. It prints in inches per second.

Fletbed Plotter:-

In this, the paper is kept in a stationary state in a bed or tray. In this, a pen is kept on one arm. Which produces a picture or figure by swirling on the X axis and Y axis on the paper with the motor. In this the pen is controlled by computer.

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